Many young scientists learn that a good scientist tries to disprove her hypothesis. This is the best way to be sure that your hypothesis is getting a rigorous test. Why do you think established scientists tell students this? Why is it a good idea?

Testing Hypothesis 1

How do you test a hypothesis? In this example, we will look into the scientific literature to find data in studies that were done using the scientific method.

To test Hypothesis 1 from the concept "Development of Hypotheses," we need to see if the amount of CO
2
gas released by volcanoes over the past several decades has increased.

To test the first, we look to the scientific literature from a site like
http://www.volcano.si.edu/education/questions/index.cfm?faq=06
. We see that the number of volcanic eruptions is about constant. We also learn from the scientific literature that volcanic gas compositions have not changed over time. Different types of volcanoes have different gas compositions, but overall the gases are the same. Another journal article states that major volcanic eruptions for the past 30 years have caused short-term cooling, not warming!

Hypothesis 1 is wrong! Volcanic activity is not able to account for the rise in atmospheric CO
2
. Remember that science is falsifiable. We can discard Hypothesis 1.

Testing Hypothesis 2

Hypothesis 2 states that the increase in atmospheric CO
2
is due to the increase in the amount of fossil fuels that are being burned. We look into the scientific literature and find this graph in the
Figure
below
.